Ethanol induces morphological and dynamic changes on in vivo and in vitro neural crest cells

Fetal alcohol syndrome (FAS) is an embryopathology related to maternal alcohol drinking. The information concerning the factors involved in the prenatal mechanisms of ethanol action at the cellular and molecular levels is scarce. Because several abnormal changes in FAS involve regions colonized by cell lineages derived from neural crest cells (NCCs), it is reasonable to propose that epigenetic alteration of this cell population can represent an important component of the etiopathogeny. The aim of this work was to evaluate the direct effect of ethanol on a chick embryo model, as well as on in vitro NCC morphology and dynamic behavior.

After ethanol treatment, in ovo or cultured chick embryos were used to determine the anatomical development of and to quantify the migratory parameters and apoptosis of NCCs. Scanning electron microscopy was performed on ethanol-perfused (and control) cultures of cephalic and trunk NCCs; the actin cytoskeleton was evaluated, and morphometric and dynamic parameters were determined after time-lapse videorecording. Recovery capacity after ethanol treatment was also determined.

Chick embryos submitted to conditions sufficient to induce FAS in mammals displayed developmental disruptions frequently accompanied by cephalic/facial anomalies. In vitro studies also indicated that cephalic and trunk NCCs exposed to ethanol exhibited significant and permanent changes regarding cell shape, surface morphology, apoptotic cell death, cytoskeleton, and distance and velocity traveled, as well as an abnormal pattern of migration.

Taking into account that even a limited period of abnormal behavior may imply serious consequences in the final cues of an embryonic cell population, our results indicate that the biological effects of ethanol on early development-even during a short time-could induce permanent ontogenetic perturbations of NCCs, with potentially dramatic effects on embryonic morphogenesis. These results support an important participation of NCCs in the etiopathogeny of FAS.